Unfortunately there isn't a method to exchange or upgrade tickets that have been purchased.
Although tickets are non-refundable, as a courtesy, if you are wishing to upgrade a previous purchase from GA to VIP (or to a pass) or any similar situation, here is the only way to do so:
Go back to the ticketing site and purchase the new level (VIP or Pass) that you wish to upgrade to as an all new purchase. You will be charged in full for this new purchased.
Reply here (start a chat on our site) with the information from the previous purchase (include your confirmation numbers and email addresses used) and we'll refund the previous purchase. This must be done before we can process a refund for the previous order.
Allow 48-72 hours for us to respond with the confirmation of the refund on the previous purchase and allow one billing cycle for the refund to appear.